如何在 Swift 中更新作业？

Question

I want to know how I can do the following:

var x = Observed<String>("hello")
label.text = x

Somewhere else x is updated:

x.value = "World"

Then label.text is automatically updated. Here is what I have for Observed so far

class Observed<T> {
    typealias Observer = (T)->()

    var observer: Observer?

    var value: T {
        didSet {
            if let observer = observer {
                observer(value)
            }
        }
    }

    init(_ v: T) {
        value = v
    }
}

I believe this is sort of what RxSwift, etc. do, but that's overkill for what I'm doing

Answer 1

You should probably just use a didSet in this scenario.

class YourClass {
   var x: String = "" { didSet {  someVC.someLabel.text = x } }
}

There is no "native" data binding in iOS as of now.

EDIT: of course there is KVO, thanks @matt for the heads-up :)